Simultaneous Optimization of Positioning and Vibration Control Using Frequency-Shaped Time-Varying Criterion Function.

Vibration Control Design for Nonlinear Systems using Frequency Response Function

A nonlinear frequency response based adaptive vibration controller is proposed for a class of nonlinear mechanical systems. In order to obtain the nonlinear Frequency Response Function (FRF), the convergence properties of the system are studied by using the convergence (contraction) theory. If the system under consideration is: 1) convergent, it directly enables to derive a nonlinear FRF for a ...

Discrete-time Frequency-shaped Sliding Mode Control for Audio-vibration Rejection in Hard Disk Drives ?

In this paper, a discrete-time frequency-shaped sliding mode control (FSSMC) is proposed for audio-vibration rejection in Hard Disk Drives (HDDs). Such vibrations cause significant degradation of the servo performance and have become a major concern in the HDD industry. The proposed FSSMC involves the frequency-shaped sliding surface design based on peak filters, aiming to provide frequency dep...

Time-Varying Monetary Policy Reaction Function: The Case of Iran

Time-Varying Modeling of Systematic Risk: using High-Frequency Characterization of Tehran Stock Exchange

We decompose time-varying beta for stock into beta for continuous systematic risk and beta for discontinuous systematic risk. Brownian motion is assumed as nature of price movements in our modeling. Our empirical research is based on high-frequency data for stocks from Tehran Stock Exchange. Our market portfolio experiences 136 days out of 243 trading days with jumps which is a considerable rat...

Adaptive Simultaneous Precision Positioning and Vibration Control of Intelligent Composite Structures

This paper presents an adaptive control scheme for simultaneous precision positioning and vibration suppression of intelligent structures. First, the structure and materials system of an active composite panel with piezoelectric ceramic patches are introduced. An adaptive control scheme, which consists of an adaptive feedback and two adaptive feedforward controllers, is then proposed. The two a...